Gas prices are expected to rise by one dollar a week on the average household gas bill.

A caller asked why West Australians pay high prices for gas when there are so many natural gas reserves off the WA coast.

"It's sold at international prices and the international price of gas is increasing and will increase in the future," Mr Barnett defended.

Another caller suggested that businesses would pass on their price increases to consumers.

Mr Barnett agreed that the cost of goods and services would rise, "Any price increase like this does tend to flow through."

The Premier is defending his decision on two fronts.

Alinta Gas was demanding a price rise of 30 per cent and says the cost of buying its gas has doubled in recent years and charges to access the gas pipeline have risen by 29 per cent.

"Alinta certainly did give me a spray. I can understand their frustration, they are the meat in the sandwich, but to suggest that there be a 30 per cent increase is just unacceptable." Mr Barnett defended.

Mr Barnett was on the receiving end of scathing criticism and some colourful language from Alinta Gas after the price rise announcement.

"I think 10 per cent is obviously less than what they'd hoped for... I don't think I've even seen a company use that language towards a government. I'll dismiss it and put it to one side as the heat of the moment. I don't think it impressed too many people in the business world." Mr Barnett told Rob Broadfield on 720 ABC Mornings.

The price increase will and about 50 dollars to the yearly gas bill of an average household.